Refrigerators are appliances used to freeze or preserve food items fresh.
FIG. 1 is a diagram illustrating a freezing cycle of a conventional refrigerator.
As shown in FIG. 1, the freezing cycle includes a compressor 10 and a condenser 20. A 3-way valve 30 is installed at a rear end of the condenser 20 and two pipes 31 and 32 are connected with the 3-way valve 30 in parallel.
At the first pipe 31 may be installed a first expansion device 35 and a refrigerating compartment evaporator 50. At the second pipe 32 may be installed a second expansion device 45 and a freezing compartment evaporator 60.
The evaporator 50 is installed in the refrigerating compartment to generate and supply cool air to the refrigerating compartment. The evaporator 60 is installed in the freezing compartment to generate and supply cool air to the freezing compartment.
If both the freezing and refrigerating compartments are put into operation, refrigerant discharged from the compressor 10 is condensed at the condenser 20 and then the refrigerant is flowing to both of the first and second pipes 31 and 32 from the 3-way vale 30, such that the refrigerant is expanded at the first and the second expansion devices 35 and 45. Hence, the refrigerant is evaporated at the refrigerating compartment evaporator 50 and the freezing compartment evaporator 60 and then cool air is generated to be supplied to the refrigerating and freezing compartments.
During the operation of the refrigerator, much moisture is generated within the refrigerator and such the moisture might be flowing along the circulating cool air only to be conceived in the evaporator having a low temperature. As a result, a problem of deteriorated heat-exchange efficiency in the evaporators might arise.
To remove frost formed in the evaporator, as shown in FIG. 1, a heater is installed at a rear end of the evaporator to heighten the temperature near the evaporator. If the power is applied to the heater, the frost generated in the evaporator is removed by the heat generated by an electric wire.